For example, a notebook computer 100 as shown in FIG. 25 includes a first member (a main body) 120 that is provided with a keyboard 110 and other operation keys, and a second member (a cover) 140 that is provided with a liquid crystal display 130, with the two members connected via hinge parts 150. In this structure, the second member 140 rotates on the hinge parts 150 in the directions of the arrows, whereby the second member 140 is opened or closed. Accordingly, operation of the first member 120 is possible while the second member 140 is in an open condition. In this kind of equipment, it is required that the hinge parts 150 connect the second member 140 with the first member 120 so that the second member 140 can be opened or closed, and so that the second member 140 can be maintained at an appropriate open angle in a partially open condition. For satisfying these requirements, hinges have been developed in the past. (For example, see Patent Documents 1 and 2.)
FIGS. 26-28 show a prior hinge that includes a bracket 210 that is mounted to a first member 120, a shaft 220 that is mounted to a second member 140, a friction plate 230, and a disc spring 240.
As shown in FIGS. 26 and 29, the bracket 210 is formed by a pressed plate-like member that includes a mounting plate part 211 that is fixed to the first member 120, and a bearing plate part 212 that rises from the mounting plate part 211. The bearing plate part 212 supports the shaft 220, and has a circular axial hole 214 through which the shaft 220 penetrates. The bracket 210 is rotatable against the shaft 220, and therefore the rotation of the bracket 210 causes the rotation of the second member 140.
As shown in FIGS. 26 and 30, the shaft 220 includes a mounting part 221 that is fixed to the second member 140, and a spindle part 222 that extends from the mounting part 221 in the axial direction of the mounting part 221. The spindle part 222 penetrates through the axial hole 214 of the bracket 210 and is connected to the bracket 210 in such a way that the spindle part 222 can rotate against the bracket 210. The spindle part 222 is noncircular by being cut in such a way that both sides of the cross-section are parallel to each other, so as to support the friction plate 230, the disc spring 240, and a washer 250 under a rotation-restraining condition.
The friction plate 230 is mounted to the shaft 220 in such a way that the surface of the friction plate 230 contacts the surface of the bearing plate part 212 of the bracket 210. As shown in FIGS. 26 and 31, the friction plate 230 has an axial hole 231 through which the spindle part 222 of the shaft 220 penetrates. The axial hole 231 is non-circular so as to correspond to the shape of the spindle part 222 of the shaft 220, and the friction plate 230 is supported by the spindle part 222 of the shaft 220 under a rotation-restraining condition.
The disc spring 240 is supported by the spindle part 222 of the shaft 220 under a rotation-restraining condition, as is similar to the friction plate 230. Moreover, the washer 250 is arranged behind the disc spring 240, and the tip of the spindle part 222 of the shaft 220 (the tip of the spindle part 222 is behind the washer 250) is caulked and plastically deformed, so that the disc spring 240 is compressed. Because the disc spring 240 presses the friction plate 230 in the axial direction, friction torque Tm in the rotational direction (see FIG. 28) is generated between the friction plate 230 and the bearing plate part 212 of the bracket 210, whereby the shaft mounting part 221 (the second member 140) can be stopped at a specified angle.